This invention relates to certain substituted 3-cyano quinoline compounds as well as the pharmaceutically acceptable salts thereof. The compounds of the present invention inhibit the HER-2 and epidermal growth factor receptor (EGFR) enzyme thereby inhibiting the abnormal growth of certain cell types. The compounds of this invention are anti-cancer agents and are useful for the treatment of cancer in mammals. This invention also relates to the use of 3-cyano quinolines in the treatment of cancer and the pharmaceutical preparations containing them.
Protein tyrosine kinases are a class of enzymes that catalyze the transfer of a phosphate group from ATP to a tyrosine residue located on a protein substrate. Protein tyrosine kinases clearly play a role in normal cell growth. Many of the growth factor receptor proteins function as tyrosine kinases and it is by this process that they effect signaling. The interaction of growth factors with these receptors is a necessary event in normal regulation of cell growth. However, under certain conditions, as a result of either mutation or over expression, these receptors can become deregulated, the result of which is uncontrolled cell proliferation which can lead to tumor growth and ultimately to the disease known as cancer [Walks, A. F., Adv. Cancer Res., 60, 43 (1993) and Parsons, J. T.; Parsons, S. J., Important Advances in Oncology, DeVita, V. T. Ed., J.B. Lippincott Co., Phila, 3 (1993)]. Among the growth factor receptor kinases and their proto-oncogenes that have been identified and which are targets of the compounds of this invention are the epidermal growth factor receptor kinase (EGF-R kinase, the protein product of the erbB oncogene), and the product produced by the erbB-2 (also referred to as the neu or HER-2) oncogene. Since the phosphorylation event is a necessary signal for cell division to occur and since over expressed or mutated kinases have been associated with cancer, an inhibitor of this event, a protein tyrosine kinase inhibitor, will have therapeutic value for the treatment of cancer and other diseases characterized by uncontrolled or abnormal cell growth. For example, over expression of the receptor kinase product of the erbB-2 oncogene has been associated with human breast and ovarian cancers [Slamon, D. J., et. al., Science, 244, 707 (1989) and Science, 235, 1146 (1987)]. Deregulation of EGF-R kinase has been associated with epidermoid tumors [Reiss, M., et al., Cancer Res., 51, 6254 (1991)], breast tumors [Macias, A., et. al., Anticancer Res., 7, 459 (1987)], and tumors involving other major organs [Gullick, W. J., Brit. Med. Bull., 47, 87 (1991)]. Because of the importance of the role played by deregulated receptor kinases in the pathogenesis of cancer, many recent studies have dealt with the development of specific PTK inhibitors as potential anti-cancer therapeutic agents [some recent reviews: Burke. T. R., Drugs Future, 17, 119 (1992) and Chang, C. J.; Geahlen, R. L., J. Nat. Prod., 55, 1529 (1992)]. The compounds of this invention inhibit the kinase activity of EGF-R and are therefore useful for treating certain disease states, such as cancer, that result, at least in part, from deregulation of this receptor.
The HER-2 gene (c-erbB-2, neu) encodes a 185 kDa transmembrane tyrosine kinase receptor that has partial homology with other members of the epidermal growth factor receptor family [Shih, C., Padhy, L. C., Murray, M., et al. Transforming genes of carcinomas and neuroblastomas introduced into mouse fibroblasts, Nature, 290, 261-264 (1981)]. It is now known that normal human cells express a small constitutive amount of HER-2 protein on the plasma membrane. The activation of the HER-2 oncogene is believed to follow the binding of a yet unidentified growth factor ligand to the HER-2 receptor complex, which leads to heterodimerization, triggering a cascade of growth signals that culminates in gene activation. More specifically, the epidermal growth factor family can be subdivided into four groups based on their receptor-binding specificities (HER-1, HER-2, HER-3, and HER-4). HER-2 is the preferred heterodimerization partner of all other HER receptors. Over expression of HER-2 has been demonstrated to lead to increased tumorigenicity, tumor invasiveness, increased metastatic potential, and altered sensitivity to hormonal and chemotherapeutic agents in transfection studies in cellular and animal models [Pegram, M. D., Finn, R. S., Arzoo, K., et al. The effect of HER-2/neu over expression on chemotherapeutic drug sensitivity in human breast and ovarian cells Oncogene, 15, 537-547 (1997)].
HER-2 protein over expression has been reported to occur in approximately 30% of invasive human breast cancers, with HER-2 gene amplification detected in 95% or more of the specimens found to over express HER-2 protein, [Gebhardt, F., Zänker, K., Brandt, B. Differential expression of alternatively spliced c-erbB-2 mRNA in primary tumors, lymph node metastases, and bone marrow micro metastases from breast cancer patients Biochem. Biophys. Res. Commun., 247, 319-323 (1998)].
U.S. Pat. No. 6,288,082 issued Sep. 11, 2001 (the '082 patent) discloses substituted 3-cyano quinoline compounds that inhibit epidermal growth factor receptor (EGFR). The compounds of this application are distinguished from those of the '082 patent in their ability to act as potent HER-2 inhibitors.